The rubble of the World Trade Centre smoulders after the 9/11 terrorist attack. Photograph: Alex Fuchs/AFP

On 11 September 2001, I lost my husband. He was a passenger aboard United Airlines flight 175 when it was flown into the south tower of the World Trade Centre. He was a professor of cultural geography and would have been the very person his family, colleagues, friends and students would have sought out on 9/11 to help us better comprehend the events of that horrific day.

As a colleague said at his memorial service, because he had devoted his life to trying to know and understand the perspectives of others, he would have been able to help us understand the grievances of some against our government, grievances that they obviously felt justified the violent and terrible taking of the lives of more than 3,000 civilians. Unlike those who attacked us, Robert believed in the importance and necessity of seeking justice, but not in revenge.

I, along with the members of September 11th Families for Peaceful Tomorrows, support the position that Khalid Sheikh Mohammed and the four detainees charged with 9/11 crimes should be tried in federal courts and not in military tribunals. This was the promise made to us by Barack Obama throughout his campaign, and by Attorney General Eric Holder, as the justice department began its inquiry into the process of closing Guantánamo Bay. Then, closing Guantánamo Bay was a promise to keep faith with the American people that we are a nation of laws, laws that determine and reflect our best qualities, laws that we aspire to live by.

Since 9/11, criminals have been successfully prosecuted in our civilian courts, yet we continue to detain human beings outside of our borders, outside of our view and outside of our Constitution. Since 9/11, our country has been locked into this problematic binary of political bipartisanship. And since 9/11, the world has been a poorer place because of all we have lost, personally and collectively.

This week, Eric Holder himself acknowledged that he still believes the best venue for the prosecution of the 9/11 suspects is in the federal courts. That suggests his change of heart arises more from political pressure than a loss of faith in our judicial system. Going forward, we hope there will be no further excuses used to prevent the remaining detainees from being tried in the federal courts, which as the record has shown, have successfully adjudicated terrorism trials. We cannot continue to let politics subvert our system of justice.

We, the members of September 11th Families for Peaceful Tomorrows want our nation back. We want the rule of law restored. The right thing to do is to close Guantánamo Bay and work within the system of justice and our long-established rule of law.